1. Field of the Invention
The present invention relates to a system for purging air from an enclosed volume of space, such as the interior of a vehicle.
2. Discussion of Related Art
It is a well-known phenomenon that the cabin of a vehicle, such as an automobile, is often subjected to an abnormal increase in temperature when the vehicle is turned off and is standing under the scorching heat of the sun. Under hot soak conditions caused by high temperatures and sun load, the average temperature of the vehicle can increase by as much as 50 to 60xc2x0 F. above the outside or ambient temperature. The increase in temperature lengthens the amount of time to comfort the occupants of the vehicle at the time of start up of the vehicle. In addition, when the vehicle has been exposed to hot soak conditions for long periods of time, such as several hours, the seats and interior of the vehicle become thoroughly heated to the higher temperature and, thus, increase the amount of time for reaching a level of comfort for the occupants.
One prior attempt at decreasing the amount of time for reaching a level of comfort for the occupants, is to use a pair of blowers that are powered by a solar panel. The blowers purge the hot air within the interior of the vehicle beginning from the time that the vehicle is turned off. Powering the blowers with a solar panel conserves the energy of the vehicle""s battery used to start the vehicle. One disadvantage of this system is that it requires additional components than those that are normally available for a commercial vehicle. The additional components result in a more expensive and complicated vehicle.
It is also well known in the art that purging air from within the interior of a vehicle can be performed to improve the operation of so called electronic automatic temperature control (xe2x80x9cEATCxe2x80x9d) systems. Such EATC systems measure the temperature of the interior of a vehicle. The measured temperature is used by the EATC system to activate subsystems, such as ventilation mode, recirculation door positions, blower speeds and refrigeration cycles, which will lower or raise the interior compartment temperature to meet passenger expectations. Relevant subsystems of the EATC system include ventilation mode, recirculation door positions, blower speeds and refrigeration cycles.
Typically, a sensor or thermosistor measures the temperature of the interior compartment of the vehicle. Before the interior compartment temperature may be accurately measured, air in the immediate area of the sensor must be purged in favor of air pulled in from the interior compartment.
With regard to conventional EATC systems, purging does not typically begin until after the EATC is activated, which occurs after the ignition system of the vehicle is activated. However, it has been suggested to start the purging process before passengers are inside the vehicle and before the vehicle""s EATC system is actually started, so that more accurate temperature readings may be made.
One disadvantage of the above-described systems is that they require separate power supplies for the purge system that are separate from the battery of the vehicle which results in an increase in the cost and complexity of a purge system.
In view of the above-described disadvantage, it is an object of the present invention to provide an improved temperature control device for the interior of a vehicle.
It is another object of the present invention to reduce the amount of discomfort an individual feels when entering a vehicle that has been exposed to the sun and/or heat.
It is another object of the present invention is to provide an air purge system that can safely be run off of a vehicle""s battery during the time period that a vehicle is turned off.
One aspect of the present invention regards an air purge system that includes a first sensor for sensing a first physical property within an enclosed volume of space and a second sensor for sensing a second physical property outside of the enclosed volume of space. A blower is in fluid contact with both the enclosed volume of space and outside of the enclosed volume of space. A processor connected to the first and second sensors and the blower, wherein the processor calculates a difference between the first and second physical properties and activates the blower if the difference is greater than or equal to a predetermined value.
A second aspect of the present invention regards a method of purging air that includes sensing a first physical property within an enclosed volume of space, sensing a second physical property outside of the enclosed volume of space, calculating a difference between the first and second physical properties; and conveying air out of the enclosed volume of the space if the difference is greater than or equal to a predetermined value.
A third aspect of the present invention regards an air purge system that includes a blower that is in fluid contact with both an enclosed volume of space and outside of the enclosed volume of space, a power supply connected to the blower and a processor connected to the first and second sensors, the blower and the power supply; wherein the processor activates the blower and senses the power level of the power supply and deactivates the blower should the power level fall below a predetermined power level.
A fourth aspect of the present invention regards a method of purging air that includes activating a blower so as to convey air from an enclosed volume of space to outside of the enclosed volume of space, sensing a power level of a power supply connected to the blower and deactivating the power supply should the sensed power level fall below a predetermined power level.
Each of the above aspects of the present invention provides the advantage of decreasing the cost and complexity of a purge system.
The above third and fourth aspects of the present invention provide the advantage running a purge system off of the battery used to start a vehicle.
The present invention, together with attendant objects and advantages, will be best understood with reference to the detailed description below in connection with the attached drawings.